CA1111163A - Polymerisation of vinyl monomers - Google Patents
Polymerisation of vinyl monomersInfo
- Publication number
- CA1111163A CA1111163A CA317,607A CA317607A CA1111163A CA 1111163 A CA1111163 A CA 1111163A CA 317607 A CA317607 A CA 317607A CA 1111163 A CA1111163 A CA 1111163A
- Authority
- CA
- Canada
- Prior art keywords
- process according
- reaction
- monomer
- emulsifier
- vinyl aromatic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F12/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring
- C08F12/02—Monomers containing only one unsaturated aliphatic radical
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Paper (AREA)
Abstract
A B S T R A C T
An emulsion polymerisation process comprises subjecting an intimate aqueous dispersion of monomer material comprising at least one vinyl aromatic monomer, optionally with unsaturated nitrile or conjugated diene comonomer to a rapid polymerisation, preferably adiabatic, in the presence of a particular emulsifier system in a continuous flow agitated reaction carried out at 80°C to 100°C. The thermoplastic product in latex form is continuously removed and is ideal for use in reinforcing rubber latices. An advantage is that a small reactor may be used to obtain a large throughput.
An emulsion polymerisation process comprises subjecting an intimate aqueous dispersion of monomer material comprising at least one vinyl aromatic monomer, optionally with unsaturated nitrile or conjugated diene comonomer to a rapid polymerisation, preferably adiabatic, in the presence of a particular emulsifier system in a continuous flow agitated reaction carried out at 80°C to 100°C. The thermoplastic product in latex form is continuously removed and is ideal for use in reinforcing rubber latices. An advantage is that a small reactor may be used to obtain a large throughput.
Description
- 2 ~ his inverltion relates to the polymerisation of at least one vinyl monomer in emulsion to obtain a -thermoplastic product. In a particular embodiment it relates to the polymerisation of a vinyl aromatic monomer,especial]y styrene, to obtain a thermoplastic polymer in latex form which iS particularly useful as a reinforcing agent for rubber latices.
It is well known to polyrnerise vinyl monomers in errlulsion.
Thus styrene-butadiene rubbers are prepared commercially in emulsion on a large scale. Thermop].astics such as acrylonitrile-butadiene-- .
styrene (ABS) resin and polystyrene and styrene-acrylonitrile copol~er may also be prepared in emulsion.
Thermoplastic polymers and copolymers of a viny]. aromatic monomer, in late~x :Lorrn, have been used for many years as reinforcing agents foI mouldetl and .spread foams based on rubber latex. The latex may be compounded with the rubber latex, or if desired may be coagglomerated with the rubber latex using, for example~ the process disclosed in British Patent specification No. 976,21~. ~or optimum reinforcement we believe that the number average particle siæe of the vinyl aromatic polymer in the latex should be in the range 1000 to 1500 Angstroms. Previously such vinyl aromatic polymer latices have been prepared by a batch reaction.
We now fi..nd that a vinyl aromatic monomer mav be poly,neri,sed or copolymerised in ernulsi.on to a therlnop:Lustic produot hnv:ing polymer partlc:le,s in the abovorllolltiolle(l ~S:i.Y,C rarlgc~ in a fast reaction carried out under continuo1ls flow conditions by adjustment and control of tl~e reacti.on. conditi.ons used.
According to the present invention an emulsion polymerisati.on process comprises (1) subjecting an inti.mate aqueous dispersion of tnonorner materi.al comprising (A) at least one vinyl aromatic monomer, 3o (B) a mixture of one of at l.east one vinyl aromatic monomer with at least one unsaturated nitril.e or (C) a mixture of at least one vinyl aromatic monomer with at least one conjugated diene, the ratio of monomers in mixtures (B) and (C) being such as to yield a thermo-plastic product, with 1.0 to 2.0 parts por hundred parts of monomer (phm) on a weight basis of primary emulsifier, 1.0 to 2.0 ph~ of secondary etnulsifier and free radical initiator, to a rapi.d polymerisation, preferably under substantially adiabatic conditions, in a continuous flow a~ritated reaction such that the reaction is carried out at ~0 C to lO0 C, and (2) continously removing the formed latex.
By the use of this process it is possible to obtain a thermoplastic vinyl polymer latex particularly useful as a reinforcing agent ~or rubber latices in a very short reaction time (less than l hour).
The process is particularly applicable to the preparation of thermoplastic polymers from styrene monomer alone or monomer mixtures comprising styrene and acrylonitrile or styrene and butadiene in appropriate ratios.
Examples of vinyl aromatic monomers, other than styrene, which may be u.sed in the process are monovinyl nromatic monorners having one or more alkyl or ha].o substi-tuents attached to the nucleus. Examples of such compounds are the ar-methyl styrenes, ar-ethyl styrenes, 2,4 dimethyl styrene, isopropyl styrene, t-butyl styrene, o-,m-and p-chlorostyrenes and 2,4 dibromostyrene. Alpha substituted vinyl aromatic monomers, such as alpha methyl styrene and alpha ethyl styrene may be used in copolyme:risations but preferably are only employed in admixture with 80~ or more of an unsubstituted or nuclear substituted vinyl aromatic monomer.
Examples of unsatllrAtod nil:ri.lec1 w~l:i.ch may be copoLynle:~i.aed with the vinyl aromnt;.c monolller(~3) in tho proce-3-3 of the invent;.on are acrylonitrile and methacrylonitrile. Normal].y the amount of unsaturated nitrile used will not exceed 30% by weight. Example~
of conjugated dienes which may be copolymerised with the vinyl aromatic monorner(s) in the process of the invention are those having up to ].0 carbon atoms, such as butadlene, which is preferred, or isoprene. Normally the amount of conjugated diene used will not exceed about 40 mole ~, thus yielding the so-called "high styrene" ~-resi.ns.
In the polymerisation of these viny]. monomers by the process of the present inverltion i-t i.5 important to h ve an intimate aqueous di.spersion of the monomers, the emulsifiers and the rree radical initiator. Preferably this is obtained by passing the aqueous mi~ture of reactants (other tlia~ initiator) through a homogeniser in the supply line to the rcaction zone (reactor). Alternatively a homogeniser in a recirclllRtoly loop rnay be used in which reactants are extracted from the reaction ~one, homogenised and then returned to the reactor, but this is lcss preferred. In either case the reaction is carried out with good agitation to maintain the intimate dispersion stable with no phase separation during reaction~
The primary emulsifier used in the process is preferably the sodil~ or potassium salt of an or~anic carboxylic acid ha~ing 12 to 20 carbon atoms or of rosin aeid. Especially suitable salts are salts of w~saturated fatty acids hlving 16 to 20 carbon atoms and in particular the sodium and potaSsillm salts of saturated or unsaturated fatty acids having 16 or 18 eal~bon atoms. A mixture of two or more salts may be used if desired. Potassium olcate is preferred. If desired it may be preplred in situ usingr oleic acid and, for example, potassium hydroxide and/or calbonate. E}.amples of suitable secondary emulsifiers are the alkali metal salts of naphthalene sulphonic acid derivatives such as the sodi~ salt of naphthalene svlphonic acid-forrnaldehyde condensate. Exlmples of such secondary emulsifiers are those available co~mercially under the trade marks bispersol, "~e~aloid"an~'Daxad." PrefeI:Ibly the ratio by ~eight of primary emulsifier to secondary cmul ifier is approximately 1.5 : 1.0 to 1.0 : 1.5, preferably they alc used in appro~imately equal amounts.
The free radical initiator l~hich i5 employed in l;he IjroceEs f the invcntion may be ally of th()E:e l~nown in ihe flrt ~hich prodllcc free radic.lls under the condili OnE~ of ~reaction. Preferably the free rsdical initiatcr is tho~mall~ decor~lposAhle~ i.e., ~Ihich produces free radicals by thermal decolllrosition. Preferred initiators in this claE~s are the sodium, }-o1:ls3ill;n and c~rnrnonium peroxydisulphates -~o ~persul}~ tesJ. ~ther exl~ le~ of initiators in thi~ c:lass are t-butyl hydrcperoxide~ t-buty~ r(~ctoclte, ben~oyl peroY.ide and dicl~lyl peroxide. ~edox inj1ia10rs may be used if desired. The ar3lc~unt of free radical initia1~n uscd in generally in the range of 0.1 to 0.10 pl~m. 0.1 to 0.30 !~h:r of potassiu3~ or a3r~rr!0ni ~5 ;-cr ull~h te is ver~ el`ferli~e.
,, i ' '' _ 5 -In common with known emulsion polymerisation techniques, it is desirable to include a molecu].ar weight modifier such as a mercaptan,for example, t-dodecyl mercaptan, or n-dodecyl mercaptan in the reaction mixture, the amount of such modifier generally being from 0.03 to 0.50 phm.
It is also desirable to in~lude an oxygen scaven~er, such as sodium dithionite (sodium hydrosulphite), in amounts of, for example, 0.02 phm, since the presence of oxygen has an inhibiting effect on the polymerisation reaction.
The process i5 carried out in a stirred reactor which, in the polymerisation of a vinyl aromatic monomer or mixture of such monomers, alone does not need to be press~re rated. ~here a diene or unsaturated nitrile is used in admixture with the vinyl aromatic monome:r(s) i.t is desirable that the reactor be pressure rated to withstand the pressuIes generated during the polymerisation which in general will not exceed 20 Atmospheres (0.203 MPa). External pressure need not be applied to the reactor. The reactor size may be quite small, for e~ample, 800 or 1000 gallon capacity. As the residence time is short, a small reactor may be used to obtain a large throughput.
~s mentioned above the intimate aqueous dispersion of the monomers the emulsifiers and the free radical initiator is preferably prepared by pa.ssing the aqueous ;nixture Or reactants (other than initi.ator) through a homogerJiser in ti~e supl):Ly lino to lh~ reuctor.
The temperature of the reaotant~ at this stagre may be in the region of 20 C to 60 C. Generally heat must be supplied Lo the reactor on start up but once the reaction is p~oceedingJthe exotherm from the heat of polymerisation is easily sufficient to keep the temperature above 80 C. In practice the heat of polymerisation evolved would be sufficient to raise the temperature of the reaction above 100 C.
The reaction temperature is however kept within the range 80C to 100 C, preferably about 90 C, by reducing the feed temperature of reactants to the reactor or by increasing the amount of water in the aqueous dispersiorl. Because of the high temperatures employed the polymerisation reaction proceeds very rapidly and it is possible to obtai.n a conve:rsion of 75% to 85~ with a residence time of less than an hour, generally less than 30 minutes.
' .
~ he pH durin~ reaction is preferably maintained above 10 in order to minimise or eliminate the possibility of coagulum formation.
This may be achieved, for example, by using an excess amount of potassium hydroxide in the in situ formation of the primary emulsifier.
The latices of vinyl aromatic polymers and copolymers obtained by the process of the invention are particularly useful as reinforcing &gents for moulded and spread fonm and if desired may be used to reinforce rubbe~ latices, for example, SBR rubber latex, by the process disclosed in ~ritish Patent specification No. 976,213.
They may also be used in blends with other latices as stiffening agents in the preparation of latcx compositions for use in paper and textile applications.
In a preferred embodiment of l;he process it is possible to obtain very lligh conversions so th.1t the need for stripping of unreacted monomers is minirnised or cven eliminated completely, with consequent energy saving and other economic advantages. In this embodiment the formed latex which is continuously removed is supplied to a finishing vessel where, by thc addition of a secon~ary catalyst, reaction may be ta~;en to substantial completion. In this way residual monomer levels of at most 0.1~ may be obtained. A suitable secondary catalyst process is that claimed in copending Canadian application No. 317,608 of Moore et ~1., filed December 8, 1978.
, - '-:' ' : - ' , ~ : , !
The following Example illustrates the invention:-EX~PI,E
A polystyrene latex was prepared by the process of the inventionemploying continuous flow and a fast reaction time.
An a~ueous dispersion was prepared to the following formulation in which parts are parts by weight dry:-Styrene 100.00 Parts Oleic acid 1.80 "
Po-tassium carbonate0.24 "
BEVALOID * solution (40~o) 2.04 "
Potassium hydroxide (50~) 0.53 Sodium hydrosulphite0.024 "
Chelating agent (50%J 0.06 "
Water 42.28 t dodecyl mer.captan0.30 * ~EVALOID (Trade Mark) is the sodi.um salt of a naphthalene-sulphonic acid-formaldehyde condensate.
This dispersion together with water (108 phm) was passed through a homogeniser, admixed with a solution of almnonium persulphate (0.12 phm) in water (2.29 phm) and continuously supplied at a ternperature of about 50 C to 60 C to a stirred tank reactor of 500 imperial gallons capacity. Af1;er ini.tiation, the temperature of the reaction mixture rose rapidly and was controlled to a temperature of aboul 90C to 95C by cooling the a~1ueou3 dispersion suppl:iod to tile .re~lctor.
After a reslderlce time of 20 tr.inutes to hal:L an hour, re~action mixture vas continuously withdrawn from the reactor. Once a steady state had been achieved i.t was found that the conversi.on of monomer to polymer latex was about 8 ~.
Polymer latex was continuously withdrawn and supplied to a large finishing vessel or unstirred tank, together with a secondary ca-talyst comprising diethylene triamine (0.12 phm), water (1.08 phm) and cumene hydroperoxide (0.].6 phm). After several hours it was found that the conversion of monomer to polymer in samples of withdra~l latex achieved substantial completion with a residual monomer content of about 0. l~o.
: .
:
It is well known to polyrnerise vinyl monomers in errlulsion.
Thus styrene-butadiene rubbers are prepared commercially in emulsion on a large scale. Thermop].astics such as acrylonitrile-butadiene-- .
styrene (ABS) resin and polystyrene and styrene-acrylonitrile copol~er may also be prepared in emulsion.
Thermoplastic polymers and copolymers of a viny]. aromatic monomer, in late~x :Lorrn, have been used for many years as reinforcing agents foI mouldetl and .spread foams based on rubber latex. The latex may be compounded with the rubber latex, or if desired may be coagglomerated with the rubber latex using, for example~ the process disclosed in British Patent specification No. 976,21~. ~or optimum reinforcement we believe that the number average particle siæe of the vinyl aromatic polymer in the latex should be in the range 1000 to 1500 Angstroms. Previously such vinyl aromatic polymer latices have been prepared by a batch reaction.
We now fi..nd that a vinyl aromatic monomer mav be poly,neri,sed or copolymerised in ernulsi.on to a therlnop:Lustic produot hnv:ing polymer partlc:le,s in the abovorllolltiolle(l ~S:i.Y,C rarlgc~ in a fast reaction carried out under continuo1ls flow conditions by adjustment and control of tl~e reacti.on. conditi.ons used.
According to the present invention an emulsion polymerisati.on process comprises (1) subjecting an inti.mate aqueous dispersion of tnonorner materi.al comprising (A) at least one vinyl aromatic monomer, 3o (B) a mixture of one of at l.east one vinyl aromatic monomer with at least one unsaturated nitril.e or (C) a mixture of at least one vinyl aromatic monomer with at least one conjugated diene, the ratio of monomers in mixtures (B) and (C) being such as to yield a thermo-plastic product, with 1.0 to 2.0 parts por hundred parts of monomer (phm) on a weight basis of primary emulsifier, 1.0 to 2.0 ph~ of secondary etnulsifier and free radical initiator, to a rapi.d polymerisation, preferably under substantially adiabatic conditions, in a continuous flow a~ritated reaction such that the reaction is carried out at ~0 C to lO0 C, and (2) continously removing the formed latex.
By the use of this process it is possible to obtain a thermoplastic vinyl polymer latex particularly useful as a reinforcing agent ~or rubber latices in a very short reaction time (less than l hour).
The process is particularly applicable to the preparation of thermoplastic polymers from styrene monomer alone or monomer mixtures comprising styrene and acrylonitrile or styrene and butadiene in appropriate ratios.
Examples of vinyl aromatic monomers, other than styrene, which may be u.sed in the process are monovinyl nromatic monorners having one or more alkyl or ha].o substi-tuents attached to the nucleus. Examples of such compounds are the ar-methyl styrenes, ar-ethyl styrenes, 2,4 dimethyl styrene, isopropyl styrene, t-butyl styrene, o-,m-and p-chlorostyrenes and 2,4 dibromostyrene. Alpha substituted vinyl aromatic monomers, such as alpha methyl styrene and alpha ethyl styrene may be used in copolyme:risations but preferably are only employed in admixture with 80~ or more of an unsubstituted or nuclear substituted vinyl aromatic monomer.
Examples of unsatllrAtod nil:ri.lec1 w~l:i.ch may be copoLynle:~i.aed with the vinyl aromnt;.c monolller(~3) in tho proce-3-3 of the invent;.on are acrylonitrile and methacrylonitrile. Normal].y the amount of unsaturated nitrile used will not exceed 30% by weight. Example~
of conjugated dienes which may be copolymerised with the vinyl aromatic monorner(s) in the process of the invention are those having up to ].0 carbon atoms, such as butadlene, which is preferred, or isoprene. Normally the amount of conjugated diene used will not exceed about 40 mole ~, thus yielding the so-called "high styrene" ~-resi.ns.
In the polymerisation of these viny]. monomers by the process of the present inverltion i-t i.5 important to h ve an intimate aqueous di.spersion of the monomers, the emulsifiers and the rree radical initiator. Preferably this is obtained by passing the aqueous mi~ture of reactants (other tlia~ initiator) through a homogeniser in the supply line to the rcaction zone (reactor). Alternatively a homogeniser in a recirclllRtoly loop rnay be used in which reactants are extracted from the reaction ~one, homogenised and then returned to the reactor, but this is lcss preferred. In either case the reaction is carried out with good agitation to maintain the intimate dispersion stable with no phase separation during reaction~
The primary emulsifier used in the process is preferably the sodil~ or potassium salt of an or~anic carboxylic acid ha~ing 12 to 20 carbon atoms or of rosin aeid. Especially suitable salts are salts of w~saturated fatty acids hlving 16 to 20 carbon atoms and in particular the sodium and potaSsillm salts of saturated or unsaturated fatty acids having 16 or 18 eal~bon atoms. A mixture of two or more salts may be used if desired. Potassium olcate is preferred. If desired it may be preplred in situ usingr oleic acid and, for example, potassium hydroxide and/or calbonate. E}.amples of suitable secondary emulsifiers are the alkali metal salts of naphthalene sulphonic acid derivatives such as the sodi~ salt of naphthalene svlphonic acid-forrnaldehyde condensate. Exlmples of such secondary emulsifiers are those available co~mercially under the trade marks bispersol, "~e~aloid"an~'Daxad." PrefeI:Ibly the ratio by ~eight of primary emulsifier to secondary cmul ifier is approximately 1.5 : 1.0 to 1.0 : 1.5, preferably they alc used in appro~imately equal amounts.
The free radical initiator l~hich i5 employed in l;he IjroceEs f the invcntion may be ally of th()E:e l~nown in ihe flrt ~hich prodllcc free radic.lls under the condili OnE~ of ~reaction. Preferably the free rsdical initiatcr is tho~mall~ decor~lposAhle~ i.e., ~Ihich produces free radicals by thermal decolllrosition. Preferred initiators in this claE~s are the sodium, }-o1:ls3ill;n and c~rnrnonium peroxydisulphates -~o ~persul}~ tesJ. ~ther exl~ le~ of initiators in thi~ c:lass are t-butyl hydrcperoxide~ t-buty~ r(~ctoclte, ben~oyl peroY.ide and dicl~lyl peroxide. ~edox inj1ia10rs may be used if desired. The ar3lc~unt of free radical initia1~n uscd in generally in the range of 0.1 to 0.10 pl~m. 0.1 to 0.30 !~h:r of potassiu3~ or a3r~rr!0ni ~5 ;-cr ull~h te is ver~ el`ferli~e.
,, i ' '' _ 5 -In common with known emulsion polymerisation techniques, it is desirable to include a molecu].ar weight modifier such as a mercaptan,for example, t-dodecyl mercaptan, or n-dodecyl mercaptan in the reaction mixture, the amount of such modifier generally being from 0.03 to 0.50 phm.
It is also desirable to in~lude an oxygen scaven~er, such as sodium dithionite (sodium hydrosulphite), in amounts of, for example, 0.02 phm, since the presence of oxygen has an inhibiting effect on the polymerisation reaction.
The process i5 carried out in a stirred reactor which, in the polymerisation of a vinyl aromatic monomer or mixture of such monomers, alone does not need to be press~re rated. ~here a diene or unsaturated nitrile is used in admixture with the vinyl aromatic monome:r(s) i.t is desirable that the reactor be pressure rated to withstand the pressuIes generated during the polymerisation which in general will not exceed 20 Atmospheres (0.203 MPa). External pressure need not be applied to the reactor. The reactor size may be quite small, for e~ample, 800 or 1000 gallon capacity. As the residence time is short, a small reactor may be used to obtain a large throughput.
~s mentioned above the intimate aqueous dispersion of the monomers the emulsifiers and the free radical initiator is preferably prepared by pa.ssing the aqueous ;nixture Or reactants (other than initi.ator) through a homogerJiser in ti~e supl):Ly lino to lh~ reuctor.
The temperature of the reaotant~ at this stagre may be in the region of 20 C to 60 C. Generally heat must be supplied Lo the reactor on start up but once the reaction is p~oceedingJthe exotherm from the heat of polymerisation is easily sufficient to keep the temperature above 80 C. In practice the heat of polymerisation evolved would be sufficient to raise the temperature of the reaction above 100 C.
The reaction temperature is however kept within the range 80C to 100 C, preferably about 90 C, by reducing the feed temperature of reactants to the reactor or by increasing the amount of water in the aqueous dispersiorl. Because of the high temperatures employed the polymerisation reaction proceeds very rapidly and it is possible to obtai.n a conve:rsion of 75% to 85~ with a residence time of less than an hour, generally less than 30 minutes.
' .
~ he pH durin~ reaction is preferably maintained above 10 in order to minimise or eliminate the possibility of coagulum formation.
This may be achieved, for example, by using an excess amount of potassium hydroxide in the in situ formation of the primary emulsifier.
The latices of vinyl aromatic polymers and copolymers obtained by the process of the invention are particularly useful as reinforcing &gents for moulded and spread fonm and if desired may be used to reinforce rubbe~ latices, for example, SBR rubber latex, by the process disclosed in ~ritish Patent specification No. 976,213.
They may also be used in blends with other latices as stiffening agents in the preparation of latcx compositions for use in paper and textile applications.
In a preferred embodiment of l;he process it is possible to obtain very lligh conversions so th.1t the need for stripping of unreacted monomers is minirnised or cven eliminated completely, with consequent energy saving and other economic advantages. In this embodiment the formed latex which is continuously removed is supplied to a finishing vessel where, by thc addition of a secon~ary catalyst, reaction may be ta~;en to substantial completion. In this way residual monomer levels of at most 0.1~ may be obtained. A suitable secondary catalyst process is that claimed in copending Canadian application No. 317,608 of Moore et ~1., filed December 8, 1978.
, - '-:' ' : - ' , ~ : , !
The following Example illustrates the invention:-EX~PI,E
A polystyrene latex was prepared by the process of the inventionemploying continuous flow and a fast reaction time.
An a~ueous dispersion was prepared to the following formulation in which parts are parts by weight dry:-Styrene 100.00 Parts Oleic acid 1.80 "
Po-tassium carbonate0.24 "
BEVALOID * solution (40~o) 2.04 "
Potassium hydroxide (50~) 0.53 Sodium hydrosulphite0.024 "
Chelating agent (50%J 0.06 "
Water 42.28 t dodecyl mer.captan0.30 * ~EVALOID (Trade Mark) is the sodi.um salt of a naphthalene-sulphonic acid-formaldehyde condensate.
This dispersion together with water (108 phm) was passed through a homogeniser, admixed with a solution of almnonium persulphate (0.12 phm) in water (2.29 phm) and continuously supplied at a ternperature of about 50 C to 60 C to a stirred tank reactor of 500 imperial gallons capacity. Af1;er ini.tiation, the temperature of the reaction mixture rose rapidly and was controlled to a temperature of aboul 90C to 95C by cooling the a~1ueou3 dispersion suppl:iod to tile .re~lctor.
After a reslderlce time of 20 tr.inutes to hal:L an hour, re~action mixture vas continuously withdrawn from the reactor. Once a steady state had been achieved i.t was found that the conversi.on of monomer to polymer latex was about 8 ~.
Polymer latex was continuously withdrawn and supplied to a large finishing vessel or unstirred tank, together with a secondary ca-talyst comprising diethylene triamine (0.12 phm), water (1.08 phm) and cumene hydroperoxide (0.].6 phm). After several hours it was found that the conversion of monomer to polymer in samples of withdra~l latex achieved substantial completion with a residual monomer content of about 0. l~o.
: .
:
Claims (9)
1. An emulsion polymerisation process which comprises (1) subjecting an intimate aqueous dispersion of monomer material comprising (A) at least one vinyl aromatic monomer; (B) a mixture of at least one vinyl aromatic monomer with at least unsaturated nitrile or (C) a mixture of at least one vinyl aromatic monomer with at least one conjugated diene,the ratio of monomers in mixtures (B) or (C) being such as to yield a thermoplastic product, with 1.0 to 2.0 parts per hundred parts of monomer on a weight basis of primary emulsifier, 1.0 to 2.0 phm of secondary emulsifier and free radical initiator to a rapid polymerisation in a continuous flow agitated reaction such that the reaction is carried out at 80°C to 100°C and (2) continuously removing the formed latex.
2. A process according to claim 1 carried out under substantially adiabatic conditions.
3. A process according to claim 1 wherein the primary emulsifier is the sodium or potassium salt of an organic carboxylic acid having 12 to 20 carbon atoms or of rosin acid.
4. A process according to claim 1 wherein the secondary emulsifier is an alkali metal salt of a naphthalene sulphonic acid derivative.
5. A process according to claim 1 wherein the ratio by weight of primary emulsifier to secondary emulsifier is 1.5 : 1 to 1 : 1.5.
6. A process according to claim 1 wherein the primary emulsifier and secondary emulsifier are used in approximately equal amounts.
7. A process according to claim 1 wherein the intimate aqueous dispersion is prepared by passing the monomer material and the emulsifiers through a homogeniser in the supply line to the reaction or in a recirculatory loop.
8. A process according to claim 1 wherein the reaction residence time is on average less than thirty minutes.
9. A process according to claim 1 wherein the reaction temperature is maintained within the range 80°C to 100°C by reducing the temperature of the aqueous dispersion supplied to the reaction or by increasing the amount of water in the aqueous dispersion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB52725/77 | 1977-12-19 | ||
| GB52725/77A GB1593778A (en) | 1977-12-19 | 1977-12-19 | Polymerisation of vinyl monomers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1111163A true CA1111163A (en) | 1981-10-20 |
Family
ID=10465047
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA317,607A Expired CA1111163A (en) | 1977-12-19 | 1978-12-08 | Polymerisation of vinyl monomers |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4239669A (en) |
| EP (1) | EP0002621B1 (en) |
| JP (1) | JPS54122388A (en) |
| BG (1) | BG40484A3 (en) |
| CA (1) | CA1111163A (en) |
| DE (1) | DE2862387D1 (en) |
| GB (1) | GB1593778A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6054984B2 (en) * | 1981-02-24 | 1985-12-03 | 旭化成株式会社 | Vinylidene chloride copolymer latex |
| US4812508A (en) * | 1985-08-09 | 1989-03-14 | Ppg Industries, Inc. | Modified rosin soaps for acrylic emulsions |
| GB2196011A (en) * | 1986-10-17 | 1988-04-20 | Zygmunt Kromolicki | Improvements in the production of graft copolymers |
| US5244926A (en) * | 1992-06-16 | 1993-09-14 | The Dow Chemical Company | Preparation of ion exchange and adsorbent copolymers |
| DE10224577A1 (en) | 2002-06-03 | 2003-12-11 | Kessler Kg Maschf | Device for machining workpieces and machine arrangement therefor |
| EP1860122A1 (en) * | 2006-05-24 | 2007-11-28 | Rhodia Recherches et Technologies | Process of making aqueous dispersions of polymers, emulsions polymers and use thereof |
| US7923426B2 (en) * | 2008-06-04 | 2011-04-12 | The Procter & Gamble Company | Detergent composition |
| KR101950705B1 (en) | 2015-11-30 | 2019-02-21 | 주식회사 엘지화학 | Preparation method low styrene butadiene rubber |
| KR101950707B1 (en) | 2016-11-10 | 2019-02-21 | 주식회사 엘지화학 | Styrene-butadiene rubber compound and rubber composition for tire bead filler comprising the same |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2496222A (en) * | 1947-06-17 | 1950-01-31 | Shell Dev | Continuous process for emulsion polymerization of unsaturated compounds |
| US2631142A (en) * | 1949-06-15 | 1953-03-10 | Polymer Corp | Catalyst activator for diolefin polymerization |
| US3651037A (en) * | 1969-09-30 | 1972-03-21 | Du Pont | Process for preparing high-solids chloroprene polymer latex |
| US3651038A (en) * | 1969-09-30 | 1972-03-21 | Du Pont | Process for preparing high-solids chloroprene polymer latex |
| US4016348A (en) * | 1972-02-22 | 1977-04-05 | Adams George F | Reactor process and apparatus for continuous polymerization |
| JPS5156889A (en) * | 1974-11-14 | 1976-05-18 | Atsumi Kimimura | DODENHIMAKUKEISEISEIEMARUJON |
-
1977
- 1977-12-19 GB GB52725/77A patent/GB1593778A/en not_active Expired
-
1978
- 1978-12-08 CA CA317,607A patent/CA1111163A/en not_active Expired
- 1978-12-18 EP EP78300847A patent/EP0002621B1/en not_active Expired
- 1978-12-18 DE DE7878300847T patent/DE2862387D1/en not_active Expired
- 1978-12-18 JP JP15505178A patent/JPS54122388A/en active Pending
- 1978-12-19 US US05/971,095 patent/US4239669A/en not_active Expired - Lifetime
- 1978-12-19 BG BG7841792A patent/BG40484A3/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54122388A (en) | 1979-09-21 |
| EP0002621B1 (en) | 1984-03-14 |
| BG40484A3 (en) | 1986-12-15 |
| DE2862387D1 (en) | 1984-04-19 |
| GB1593778A (en) | 1981-07-22 |
| US4239669A (en) | 1980-12-16 |
| EP0002621A1 (en) | 1979-06-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3498942A (en) | Emulsion polymerization of unsaturated monomers utilizing alkyl sulfide terminated oligomers as emulsifiers and resulting product | |
| US3575913A (en) | Stable latex for paper coating compositions | |
| US5191008A (en) | Process for the production of latexes by the selective monomer addition | |
| US3324066A (en) | Process for preparing interpolymer latexes by incremental monomer addition | |
| CA1111163A (en) | Polymerisation of vinyl monomers | |
| US3442979A (en) | Thermoplastic-elastic moulding compositions with improved notched bar impact strength | |
| FI83328C (en) | Process for the preparation of stable aqueous polymer dispersions containing an alkenyl aromatic compound which is polymerized | |
| US3865772A (en) | Polymerization process | |
| US3219588A (en) | Catalysts for the polymerization of vinyl monomers | |
| US3458466A (en) | Method for preparing latexes having improved properties | |
| CA1137672A (en) | Process for the production of speck-free rubber latices having high surface tension | |
| US5177164A (en) | Process for shortstopping an emulsion polymerization | |
| US4002812A (en) | Production of uniform copolymer of acrylonitrile and aromatic olefines | |
| US2409915A (en) | Process for preparing rubberlike materials | |
| US4404338A (en) | Process for preparing copolymers of vinyl-aromatic monomers with ethylenically unsaturated nitriles having low content of unreacted residual monomers | |
| US3488338A (en) | Short-stopping the polymerization of chloroprene | |
| US2715115A (en) | Catalyst system for the emulsion copolymerization of butadiene and styrene | |
| US2624724A (en) | Polymerization of vinyl chloride in an aqueous emulsion | |
| US2398321A (en) | Copolymers of diolefinic compounds | |
| US3833532A (en) | Latex preparation | |
| US2801992A (en) | Suspension stabilizer of magnesium hydroxide and excess alkali | |
| US2581094A (en) | Preparation of drying oils | |
| US2707180A (en) | Chloroprene emulsion polymerization process | |
| US3179613A (en) | Metal salts of oligomeric styrene polymer in olefinic emulsion polymerization process | |
| US2996480A (en) | Method of inhibiting exothermic reaction in butadiene rubber emulsion polymerizations |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |